[flying_sloth]

Hi everyone, I went to change my brake pads and discovered that the caliper had a piston and a pin sticking. I got those out and ordered new seals for the pistons and slider pins. Now I'm wondering if should replace the pistons themselves too.

I sprayed them with brake cleaner and used a paper towel to wipe them down which cleaned most of the stuff on them, but they don’t look completely clean.

I’ve read that people use steal wool or even sand paper the pistons but I’m a bit wary of doing that? Any advice on how to clean them or should I just buy new ones

 

[SoakedKarma]

can you feel a difference where they are discolored? Rubbing/buffing compound may help
Pitting is your worst enemy, which I don't see..
imo I would reuse what you have, but your fingers are the final judge for smoothness..
coat new seals with brake fluid to allow easier insertion of pistons

0000 steel wool wouldn't hurt if used sparingly, sandpaper gawd No..

 

[flying_sloth]

One of them feels smooth all around, the other feel a little bit rough in this one spot (this is piston that was stuck)

 

[SoakedKarma]

judgement call.. only you can feel it and be the judge..
when in doubt i prefer to replace, your life can depend on brakes..
if it was higher up where dust seal rides I wouldn't be concerned, looks to be where brake fluid seal rides..

 

[flying_sloth]

judgement call.. only you can feel it and be the judge..
when in doubt i prefer to replace, your life can depend on brakes..
if it was higher up where dust seal rides I wouldn't be concerned, looks to be where brake fluid seal rides..

Yeah I get that, I will try the steel wool and see if it makes a difference. But I'm leaning towards buying one, i definitely don't wanna cheap out on my brakes. Thank you!

 

[SoakedKarma]

use steel wool radially around the circumference as you polish avoiding length wise marks..
I'm cheap and would try buffing before replacement

 

[redeemer1972]

I see nothing wrong.
Polish them up with chrome polish and put them back in.

What is way more important is the seats in the caliper that store the seals. Make sure to get all the corrosion out! They must be as clean as possible!

 

[flying_sloth]

I see nothing wrong.
Polish them up with chrome polish and put them back in.

What is way more important is the seats in the caliper that store the seals. Make sure to get all the corrosion out! They must be as clean as possible!

thank you! good to know. I have been working on cleaning the place were the seal sits with a dentist tool. The one where the piston was stuck was very dirty, I have done good progress but I can still see some junk in there